The number of sexual assaults reported on the campuses of the nation’s military academies increased by nearly a quarter over the 2010-2011 academic year, according to an annual Pentagon survey released Friday.

The dramatic increase was recorded despite efforts that defense officials have put into sexual assault awareness programs and other training to try to prevent rape and harassment on campus.

Defense Secretary Leon Panetta, in a memorandum to top Pentagon officials, expressed disappointment with the report, saying it pointed to a “persistent problem.”

But military officials who announced the results of the survey, which Congress has required the Pentagon to conduct for the past five years, attempted to put a positive spin on the report, noting that the Pentagon has been encouraging assault victims to have the confidence to come forward and report the crimes.

“A strategic priority for the Department is to increase the number of sexual assault reports made to authorities by victims in order to provide them with needed support and services,” according to the report, entitled Annual Report on Sexual Harassment and Violence at the Military Service Academies.

Now, defense officials say, that is precisely what has happened: Reports are on the rise.

“We view an increase in reports to be a positive trend” because it is indicative “of an increase in victim confidence,” said Maj. Gen. Gary Patton, director of the Department of Defense Sexual Assault Prevention and Response Office.

It is positive, too, Patton argued at a Pentagon briefing Friday afternoon, because that means the victim who has made the report is receiving “some sort of care.”

Even so, Secretary Panetta expressed dismay at the figures themselves, which also showed that more than half of all women and 10 percent of men said they had been sexually harassed in the past 12 months.

The response rate to the survey among the male and female students at the US military academies ranged from 67 to 88 percent.

Despite “our considerable and ongoing efforts,” this year’s report “demonstrates that we have a persistent problem,” Mr. Panetta wrote in a memorandum to the service secretaries that accompanied the investigation.

“I am concerned that we have not achieved greater progress in preventing sexual assault and sexual harassment among academy cadets and midshipmen.”

Patton said that he believes the reasons for the steady increase in reports is indicative of a societal problem and that the service academies grapple with sexual assault in the same way universities across the nation do.

Organizations that advocate for victims of sexual assault also point out that the students who choose to attend taxpayer-funded military academies voluntarily submit themselves to a more rigid code of conduct and discipline.

“We have to hold ourselves to a higher standard,” Patton said, adding that the academies are cultivating the future leaders of America.

Sexual assault victim advocates say they were greatly concerned by the report’s findings.

“It validates our worst fears and what we know to be true because of the number of frantic calls and emails we receive from active duty personnel,” Nancy Parrish, president of the advocacy group Protect our Defenders, said in a statement.

The spike in the report is caused by “a culture of high tolerance for rape and sexual predators in the ranks that pervades the military,” argued Parrish, adding that victims who report the crime often face retaliation “including victim-blaming, isolation, and bad performance reviews.”

Others point to the fear among victims that if they do report the crime, the perpetrators will not be prosecuted.

A Pentagon official says that reports of sexual assault at the military academies prompted 40 investigations this year, and of those, eight went to court-martial proceedings.

Panetta for his part directed the academies to identify “new ways to advance a climate of dignity and respect” on campus “to create sustainable change to academy culture that specifically will lower the prevalence and increase reporting of sexual assault and sexual harassment.”

He asked officials to report back to him on the progress of these initiatives by the end of March.